This invention relates to a kitchen ventilator having a removable grease extractor of the baffle type which abruptly changes the direction of flow of a stream of contaminated air to extract grease, dust and lint particles by centrifugal force, as distinguished from a porous filter type extractor.
It is common practice to make porous filter type grease extractors removable for cleaning but such devices have a very low effeciency in comparison with baffle type extractors, with respect to their effectiveness in removing grease and other contaminants from an air flow in a kitchen ventilator associated with cooking equipment in a restaurant. There are also hybrid types which have been made removable, having a multitude of small, angular baffles which divide the air stream into parallel zigzag paths for a short distance. These baffles are mounted in shallow frames resembling filter frames.
On the other hand it has been the practice heretofore to provide spray nozzles in the ventilator for cleaning the baffle plates in a baffle type grease extractor where the direction of the whole flow of contaminated air is abruptly changed repeatedly over a considerable distance for extraction by centrifugal force. Such nozzles are supplied with hot water and detergent to clean off the grease while the baffles remain in their normal operative positions within the ventilator.
Such nozzles are also usually used for fire extinguishing purposes and complicated control systems are necessary to schedule washing and drying cycles, including control of the ventilating fan, and the fire extinguishing system. Means must be provided for disposal of the spray water. Hence baffle type grease extractors, which change the direction of the whole flow of air over a considerable distance of travel, though far superior to porous filter type extractors and the hybrid types, have become very complicated and expensive.
Although baffle type grease extractors have been made with some of the baffles removable, other baffles then remain in their fixed positions in the ventilator and must be cleaned in such positions by one means or another. For cleaning purposes there is no advantage in being able to remove some of the baffles if they cannot all be removed.
Thus there is a need, particularly in small restaurants, for a less complicated and expensive kitchen ventilator having a removable baffle type grease extracor which can be cleaned by hand without requiring washing nozzles and automatic washing and drying cycles controlled by numerous valves and switches.